Rainbow: Nisha Rokubou no Shichinin

Japan, 1955. Six teenagers convicted of serious crimes are sent to Shounan Special Reform School and locked together in Cell 6, Block 2. There they meet Rokurouta Sakuragi, an older inmate and former boxer who refuses to let the institution strip them of the belief that life can continue beyond its walls.

The seven endure violence, humiliation, and abuse from adults who hold almost absolute power over them. Surviving depends less on strength than on the loyalty they build inside the cell, where Sakuragi becomes mentor, protector, and older brother. They make a promise to meet again after release, but freedom brings struggles of its own. Their bond must survive not only prison, but poverty, grief, broken dreams, and a postwar society that offers damaged young men few easy second chances.